[3.x] CI: Bump actions/checkout and Ubuntu versions

.github/workflows/ci.yml

@@ -5,10 +5,10 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v5
 
       - name: Install dependencies
         run: |

.github/workflows/sync_class_ref.yml

@@ -17,10 +17,10 @@ jobs:
 
     steps:
       - name: Checkout the documentation repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v5
 
       - name: Checkout the engine repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v5
         with:
           repository: 'godotengine/godot'
           # Use the appropriate branch for the documentation version.